My new palm drill arrived today. I think I'll soon be wondering how I ever got along without one. Its small size and hi speed is already proving useful. I got one seat back complete with everything clecoed together and ready for riveting. I deviated from the plans slightly on the seat back brace. I elected to dimple the brace instead of countersinking the thin .036 material. Then I countersunk the .125 thick stiffeners on both sides to accept the dimple and opposing double flush shop head. The final result came out nice.